Facebook and Google don’t expect 80 weeks and they do leet code interviews. I’d think most people do 40 hour weeks there.

I'm doing the hiring for a small company. We do coding tests as part of our interview process. I know it can show false negatives but it rarely shows false positives (wrt coding ability).

However, we don't ask employees to work anything like 80 hours a week. In fact, we track overtime hours (> 40hrs/wk) and pull the red "panic" lever when it goes above a threshold as a control for burnout.

But like you said, you're applying a filter too (if no coding test -> low overtime required). It probably has false negatives (my company), but it's worth it for you because you have found that it rarely shows false positives.

Almost nobody would stay productive coding 80 hours per week.

Almost nobody is productive past the 30 hours a week stage (excl meetings and lunch hour and whatnot).